Laravel Carbon在字符串错误时约会diffInDays（）

Question

I need to find the difference between the two dates. Say i have 2017-02-01 - 2017-01-01. The number of days between the two days is the output

$formatted_dt1=Carbon::parse($a->date)->format('Y-m-d');
$formatted_dt2=Carbon::parse($c->dt)->format('Y-m-d');
$date_diff=$formatted_dt1->diffInDays($formatted_dt2);

If I give the above code I get the error as

FatalThrowableError in ReportsController.php line 67:
Call to a member function diffInDays() on string

Answer 1

Carbon format() function will convert to string so remove format('Y-m-d') like this:

$formatted_dt1=Carbon::parse($a->date);

$formatted_dt2=Carbon::parse($c->dt);

$date_diff=$formatted_dt1->diffInDays($formatted_dt2);

Hope you understand. You can see docs here.